首先，我们先看文档
文档中百度翻译了一下，大意是：，
除了支持的映射参数外，不能更改现有字段的映射或字段类型。更改现有字段可能会使已编制索引的数据无效。
如果需要更改字段的映射，请使用正确的映射创建一个新索引，并将数据重新索引到该索引中。
重命名字段将使已在旧字段名下编制索引的数据无效。而是添加一个别名字段来创建备用字段名。
在es中，是不支持更改现有字段的映射或字段类型的，如果我们非得需要更改字段的类型，怎么办，数据迁移，重建索引，建立我们想要的正确的映射规则；
1，查看旧的索引
GET /customer/_mapping
{
"customer" : {
"mappings" : {
"properties" : {
"addr" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
}
},
"age" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
},
"fielddata" : true
},
"content" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
}
},
"interests" : {
"type" : "text",
"fielddata" : true
},
"name" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
}
},
"properties" : {
"properties" : {
"content" : {
"properties" : {
"analyzer" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
}
},
"search_analyzer" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
}
},
"type" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
}
}
}
}
}
},
"sex" : {
"type" : "text",
"fields" : {
"keyword" : {
"type" : "keyword",
"ignore_above" : 256
}
}
}
}
}
}
}
2，创建新的索引
PUT /new_customer
{
"mappings": {
"properties": {
"addr": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"age": {
"type": "integer",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"content": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"interests": {
"type": "text",
"fielddata": true
},
"name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"properties": {
"properties": {
"content": {
"properties": {
"analyzer": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"search_analyzer": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"type": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
}
}
},
"sex": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
}
}
3,数据迁移
POST _reindex
{
"source": {
"index": "customer"
},
"dest": {
"index": "new_customer"
}
}
比如，我们在老索引中进行age聚合：
GET /customer/_search
{
"query": {
"match_all": {}
},
"aggs": {
"ageAgg":{
"terms": {
"field": "age",
"size": 10
},
"aggs": {
"ageave": {
"avg": {
"field": "age"
}
}
}
}
}
}
{
"error" : {
"root_cause" : [
{
"type" : "illegal_argument_exception",
"reason" : "Expected numeric type on field [age], but got [text]"
}
],
"type" : "search_phase_execution_exception",
"reason" : "all shards failed",
"phase" : "query",
"grouped" : true,
"failed_shards" : [
{
"shard" : 0,
"index" : "customer",
"node" : "pWQJLIs9RbmQ5CrTldrIiQ",
"reason" : {
"type" : "illegal_argument_exception",
"reason" : "Expected numeric type on field [age], but got [text]"
}
}
],
"caused_by" : {
"type" : "illegal_argument_exception",
"reason" : "Expected numeric type on field [age], but got [text]",
"caused_by" : {
"type" : "illegal_argument_exception",
"reason" : "Expected numeric type on field [age], but got [text]"
}
}
},
"status" : 400
}
age是text类型的，我们把age改成了int类型的后，在进行聚合就不会报错了
{
"took" : 2,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 8,
"relation" : "eq"
},
"max_score" : 1.0,
"hits" : [
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "4",
"_score" : 1.0,
"_source" : {
"name" : "nadia",
"sex" : "gril",
"age" : 31
}
},
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "5",
"_score" : 1.0,
"_source" : {
"name" : "jxx",
"sex" : "gril",
"age" : 45,
"addr" : "北京"
}
},
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "7",
"_score" : 1.0,
"_source" : {
"name" : "abb",
"sex" : "boy",
"age" : 35,
"addr" : "南京"
}
},
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "8",
"_score" : 1.0,
"_source" : {
"name" : "abb11",
"sex" : "boy",
"age" : 36,
"addr" : "南京"
}
},
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "2",
"_score" : 1.0,
"_source" : {
"name" : "木子小僧888666",
"sex" : "boy",
"age" : 25,
"addr" : "白宫"
}
},
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "3",
"_score" : 1.0,
"_source" : {
"name" : "特朗普",
"sex" : "boy",
"age" : 88,
"addr" : "白宫"
}
},
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "1",
"_score" : 1.0,
"_source" : {
"name" : "木子小僧666999888",
"sex" : "boy",
"age" : 30
}
},
{
"_index" : "new_customer",
"_type" : "_doc",
"_id" : "dwy-YXcB9G0dRFSpm0LY",
"_score" : 1.0,
"_source" : {
"properties" : {
"content" : {
"type" : "text",
"analyzer" : "ik_max_word",
"search_analyzer" : "ik_max_word"
}
}
}
}
]
},
"aggregations" : {
"ageAgg" : {
"doc_count_error_upper_bound" : 0,
"sum_other_doc_count" : 0,
"buckets" : [
{
"key" : 25,
"doc_count" : 1,
"ageave" : {
"value" : 25.0
}
},
{
"key" : 30,
"doc_count" : 1,
"ageave" : {
"value" : 30.0
}
},
{
"key" : 31,
"doc_count" : 1,
"ageave" : {
"value" : 31.0
}
},
{
"key" : 35,
"doc_count" : 1,
"ageave" : {
"value" : 35.0
}
},
{
"key" : 36,
"doc_count" : 1,
"ageave" : {
"value" : 36.0
}
},
{
"key" : 45,
"doc_count" : 1,
"ageave" : {
"value" : 45.0
}
},
{
"key" : 88,
"doc_count" : 1,
"ageave" : {
"value" : 88.0
}
}
]
}
}
}